1. Field of the Invention
This invention relates to a herbicidal composition and more particularly to a herbicidal composition comprising 3-[3-(4H-1,2,4-triazolyl)amino]-1-(3H)-isobenzofuranone (A) as an effective ingredient and to a herbicidal composition comprising the compound (A) and at least one compound selected from the group consisting of .alpha.,.alpha.,.alpha.-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (B), 2-(3',4'-dichlorophenyl)-4-methyl-1,2,4-oxadiazolidine-3,5-dione (C) and 2,4-bis(isopropylamino)-6-methylthio-s-triazine (D) as effective ingredients.
2. Description of the Prior Art
It is known that 3-amino-1,2,4-triazole has herbicidal activity. However, 3-amino-1,2,4-triazole shows non-selective herbicidal action due to its too large absorbability against and migration rate in a plant body and therefore it has been a problem that the compound had phytotoxicity on cultivated plants in practical use.
In the light of the problem mentioned above, the inventors have studied the matter and found that one of the derivatives of 3-amino-1,2,4-triazole, that is, 3-[3-(4H-1,2,4-triazolyl)amino]-1-(3H)-isobenzofuranone shows reduced phytotoxicity and further, the compound in combination with at least one compound selected from the group consisting of .alpha.,.alpha.,.alpha.-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (B), 2-(3',4'-dichlorophenyl)-4-methyl-1,2,4-oxadiazolidine-3,5-dione (C) and 2,4-bis(isopropylamino)-6-methylthio-s-triazine (D) exhibits a synergistic effect and reduces the problem of residue in soil. The inventors has accomplished this invention based on the discoveries described above.